Read Paul's tag line. We need to know if the text data is stored in a C string (e.g., a char array) or a String object. Most of us here are not big fans of the String class, so a char array is preferred. Assuming that's the case, investigate strtok(). A starting point might be here.

We need to see the code you are using. Before posting it, however, please read the post at the top of this Forum by Nick Gammon about how to post properly here. Following his suggestions makes it easier for us to help you.

// this block will request the time and wait for it to come back, or timeout uint32_t timerStart = millis(); requestTime(Serial); // you may be using software serial, put the name of the Software Serial instance instead of Serial while(!updateTime(Serial) && millis() - timerStart < TIMEOUT_MILLIS) // this blocks, waiting for the time to come back also, you may be using software serial, put the name of the Software Serial instance instead of Serial { // just wait a second for the time to come back from module }

First decision point:decide whether you will read the whole string from Serial, or whether you are going to extract your hours/minutes form the data as it is received.

Skip the data (in string, or on the serial port) till you get past the comma.Read number (from string or serial) into hours until you get to the colon.skip the colon.Read number into minutes until you get to the next colon.Might be easier if both hours and minutes are always exactly two digits.